"They've been supporting each other through a difficult time and they're really happy together," an insider toldPeople. "Everyone is thrilled because they're both incredibly nice people."
While Lambert is probably less than thrilled, a source told E! News she sort of saw this coming.
"[Miranda] was not surprised to hear of the romance between Blake and Gwen," the source said. "They were always pretty flirty. Miranda and Blake were on the rocks on and off and knew that this could always be a possibility."
Both Shelton and Lambert attended the 2015 CMA Awards Wednesday night -- and jokes were certainly made about their breakup -- but Stefani allegedly flew to Nashville to accompany Shelton to his afterparties. Stefani hopped on a private jet shortly after being photographed getting handsy with Shelton at a couple of Halloween parties this past weekend.
Luke Bryan, a friend of Shelton's, was in disbelief when first hearing the news that Shelton, 39, is dating Stefani, 46.
"He didn't come out about that," Bryan told E! News on the red carpet last night at the CMAs. "You're trying to trick me -- Pull up online. I need to see where Blake has stated that... It can't be true, because there's no way Blake could ever score a girl like that. It's not true."